Monospecific probes, of which monoclonal antibodies (Mab) are an example, have specific reactivity and are biochemically versatile. Such probes have become invaluable tools in such diverse fields as protein chemistry, gene cloning, and clinical therapeutics. A major obstacle to the further development of monospecific probes such as Mabs, however, is the characterization of monospecific probe reactivity. Because the generation of Mabs depends upon complex biologic processes, the characterization of novel Mabs recognizing cell membrane molecules can be unpredictable, expensive, and time-consuming. The problem is further compounded by the absence of established typing cell lines in nonhuman species. The result, at least for Mabs, is that fewer Mab are being developed.
Leukocyte Differentiation Antigen Database Workshops have made a significant contribution to biomedical research over the past 20 years. The workshops have not only created a common molecular language (CD nomenclature), but the common workshop database has reconciled seemingly unrelated molecular observations in far-ranging scientific fields. The workshops were designed to enlist multiple laboratories for flow cytometry analysis. As was observed in a recent Experimental Biology meeting, the workshops are “one of the great contributions of collaborative science in the past 50 years.”
The Leukocyte Differentiation Antigen Database workshop approach, however, has two major limitations. First, this approach encourages broad participation, but it precludes the use of rigorous quantitative flow cytometry techniques. The ultimate depth of the data for comparative and predictive purposes is limited due to the variation inherent in data compiled from multiple independent sources. Second, the “cluster method” of data analysis used in the workshops was designed primarily for “typing” cell lines. The use of cell lines typically provides binary results: that is, the cell line is either positive or negative for the expression of the antigen of interest. This approach is less applicable to nonhuman species with few well-characterized cell lines. In most species, membrane molecules must be characterized using cell populations that produce complex histograms.
Because there is no molecular “gold standard,” each newly developed monospecific probe must be assessed relative to comparisons with numerous other mono specific probes with similar reactivity. These labor-intensive comparisons are only feasible for a handful of investigators. Alternatively, the investigator can wait to submit the monospecific probe to the next workshop. Because of the complex organization of these workshops, a typical waiting time to submit an antibody can be several years. Perhaps the most worrisome trend is that fewer and fewer monospecific probes are being produced. The most commonly cited reasons are 1) the extraordinary time and effort required for antibody characterization, 2) the possibility that the antigen can not be adequately characterized, and 3) the understandable reluctance of investigators to use partially characterized monospecific probes in their work.
The invention provides a way to overcome these disadvantages and is applicable not only to monoclonal antibodies, but to any monospecific probe.